Strain gauge beams are commonly employed to measure differential pressure. The U.S. Pat. No. 4,791,818 issued on 20 Dec. 1988 discloses a differential pressure transducer with a cantilever beam 30. The sensor of U.S. Pat. No. 4,791,818 comprises a strain gauge beam 46 arranged inside a sensor body 36. An electric sensor 49 such as a piezoelectric ceramic element is affixed to the surface of the strain gauge beam 46. The arrangement employs wires 53, 54 to transmit the electric signal out of sensor body 36. A measurement of differential pressure in accordance with U.S. Pat. No. 4,791,818 is potentially influenced by the orientation of the cantilever beam sensor 30. Also, the disclosure of U.S. Pat. No. 4,791,818 lacks a sophisticated approach that allows for conversion of particularly small mechanical strains into electric signals.
The U.S. Pat. No. 5,844,141 issued on 1 Dec. 1998. U.S. Pat. No. 5,844,141 teaches a sensor 10 with two silicon layers 11a, 11b enclosing a central layer 12. The central layer 12 has two beams 16. The beams 16 of U.S. Pat. No. 5,844,141 form a resonantly vibratable stress-sensitive member. The twin vibratable beams 16 connect via electrically conductive channels 23 to an electric driving signal. The arrangement determines changes in pressure from changes in the resonant frequency of the vibratable beams 16. The resonant frequency of the beams 16 of U.S. Pat. No. 5,844,141 is influenced by ambient factors such as temperature. The sensor of U.S. Pat. No. 5,844,141 thus employs a vibratable fork 20 to compensate for changes in temperature.
The U.S. Pat. No. 7,290,453B2 issued on 6 Nov. 2007. U.S. Pat. No. 7,290,453B2 discloses a pressure sensor assembly with piezo-resistive strain gauges 13 disposed on a force sensing beam. The piezo-resistive strain gauges 13, 14 of U.S. Pat. No. 7,290,453B2 are electrically arranged in a Wheatstone bridge. The Wheatstone bridge magnifies the conversion of forces into electric signals. U.S. Pat. No. 7,290,453B2 thereby tackles the challenge of efficient sensors for low pressures. The U.S. Pat. No. 7,290,453B2 acknowledges that thin diaphragms exhibit shortcomings. The specification teaches an integral diaphragm-beam and diaphragm-diaphragm approach to obviate problems related to thin diaphragms.
The U.S. Pat. No. 4,376,929 issued on 15 Mar. 1983. U.S. Pat. No. 4,376,929 teaches optimized stress and strain distribution diaphragms for pressure transducers. To that end, U.S. Pat. No. 4,376,929 discloses a plurality of recess portions 64 arranged along a cantilevered beam 61.
The patent application US2014/319628A1 was filed on 8 Apr. 2014 and was published on 30 Oct. 2014. US2014/319628A1 discloses a device with a glass substrate and with a function membrane formed on a surface of the glass substrate.
The patent application WO95/03532A1 was filed on 19 Jul. 1994 and was published on 2 Feb. 1995. WO95/03532A1 teaches a cantilevered microbeam temperature sensor.
The patent application EP1953516A1 was filed on 31 Jan. 2007 and was published on 6 Aug. 2008. EP1953516A1 deals with a micromechanical pressure sensing device.
The patent application US2011/005323A1 was filed on 8 Apr. 2009 and was published on 13 Jan. 2011. US2011/005323A1 pertains to a pressure-sensor with a mesh-like beam section.
The U.S. Pat. No. 5,177,661A was filed on 6 Mar. 1992 and issued on 5 Jan. 1993. U.S. Pat. No. 5,177,661A teaches a diaphragm pressure sensor utilizing silicon-on-insulator technology.
The patent application US2005/103114A1 was filed on 23 May 2003 and was published on 19 May 2005. US2005/103114A1 discloses a miniature sensor with a diaphragm formed by epitaxial growth of silicon.
The patent application US2016/349130A1 was filed on 27 Feb. 2015 and was published on 1 Dec. 2016. US2016/349130A1 teaches a pressure sensor.